Dan Kelly: A memorial at the WTC site would not be erected for the purpose of remembering bin Laden and his assholes, any more than the Murrah Memorial could ever be a tribute to Tim... ah... what's-his-name, I forget! ;^) It would be erected in memory of the victims, and of the bravery of the police and firefighters who died trying to help the office workers. Lots of us want to remember those who were killed, and keep them in our thoughts, not only to mourn but to move us to do everything we can to prevent terrorists from ever attacking again.

In addition to the reasons given here for cleaning up the site:

(a) I don't know if they're still holding out any hope of finding the black boxes from either airliner; it would be miraculous if any of them was still in good enough shape to extract information from. But I'll bet they're still looking anyway.

(b) The area was declared a crime scene, so perhaps they're still hoping to find clues.

(c) In addition to the bank vaults, there's merchandise in the underground shopping areas that's already been looted. I think that clearing away the debris will reduce and eventually eliminate the temptation to future looters to endanger themselves by entering the debris field.

(d) I imagine that, eventually, they will want to rebuild the underground transportation system, even if a memorial is erected at ground level.

(e) I'm sure that at least some of the victims' relatives would prefer to have their loved ones' remains interred at a family gravesite, where the relatives can mourn at a location that doesn't remind them of the horrible circumstances of the person's death. (I know that I, for one, would not want to be buried at my workplace!)